Pump, especially for pumping fuel from a storage tank to an internal

Abstract

A pump which is especially suited for pumping fuel from a storage tank to an internal combustion engine includes a rotatable impeller wheel having an annulus of impeller vanes defining respective compartments therebetween which open onto one axial surface of the impeller wheel which extends substantially normal to the axis of the rotation of the impeller wheel, and an end wall having an end surface which is juxtaposed with the axial surface of the impeller wheel and defines an interface therewith. The end wall is provided with a pumping channel which extends along a part-annular course along the trajectory of orbiting movement of the impeller vanes and opens onto the interface. The pressure of the fluid being pumped by the impeller vanes increases in the downstream direction of the pumping channel and exerts a tilting moment about an axis normal to the rotation axis on the impeller wheel. This tilting moment is counteracted by the action of a pressurized fluid confined in a pressure zone onto the axial surface of the impeller wheel, such pressurized fluid being advantageously derived from the output side of the pump. The pressure zone may be a separate additional channel of a sickle-shaped configuration situated outwardly of the pumping channel in the end wall, or a widened portion of an internal annular output channel.